The US cider market has expanded in recent years, but limited research-based information is available on fermentation management. This study investigates how apple cultivar and yeast inoculation affect the chemical and sensory properties of cider. Four ciders were produced in triplicate using combinations of two different apple cultivars - Harrison, a cider cultivar and GoldRush, a dessert cultivar - and two fermentation strategies - inoculated with dry active yeast EC1118 or Pied de Cuvé ambient fermentation. Ciders were analyzed for alcohol content, free/total SO2, titratable acidity, volatile acidity, malic acid, pH, and residual sugar. Sensory evaluation was conducted using Descriptive Analysis with trained panelists. Results were analyzed via ANOVA and Principal Component Analysis. Apple cultivar and fermentation method resulted in significant differences for chemistry and sensory parameters. Malic acid concentration was greater in the control ciders while concentrations of both residual sugar and volatile acidity were higher in the PDC ciders. The interactions effect of cultivar*fermentation method influenced both malic acid and residual sugar concentrations, where concentration differences between control and ambient ciders is smaller for GoldRush than for Harrison, showing that fermentation style produces different results across cultivars. Volatile acidity produced opposite interaction effects as differences between fermentation styles was larger for GoldRush. For sensory attributes, Harrison ciders produced high intensities for multiple attributes, but also higher variability. Multiple sensory descriptors displayed interaction effects as the fermentation method produced different results in different cultivars. This study demonstrates that increasingly popular practices in the industry can produce significantly different ciders. / Master of Science in Life Sciences / The US cider market has grown rapidly in recent years, with many new products entering the market. However, there is limited research-based information available on cider fermentation management. This study investigates how production variables, namely apple cultivar and yeast inoculation, affect the chemical and sensory properties of the cider created. The overall goal of this project is to assess the chemical and sensory characteristics that come from cider production treatments. In this study, four experimental ciders were produced using combinations of two different apple cultivars – Harrison, a cider cultivar and GoldRush, a dessert/fresh market cultivar – and two fermentation management strategies – inoculated with dry active yeast strain EC1118 or indirect inoculation through a natural fermentation method. Ciders were analyzed for alcohol content, free and total SO2, titratable acidity, volatile acidity, malic acid, pH and residual sugar. Sensory evaluation was conducted by a trained panel providing descriptive terms and intensities for each sample. Both chemical and sensory results were analyzed to reveal significant differences in samples based on not only apple type and inoculation method, but also the interactions between those two variables. This study demonstrates that increasingly popular practices in the cider industry – like natural fermentation or the use of cider-apple varieties – can produce significantly different ciders. This highlights the idea that producers need to treat each apple cultivar differently, as they behave differently throughout production.

Virginia is the largest apple producing state in the Southeast region of the United States and ranks 10th in most cideries in the US. Natural, or un-inoculated, fermentation methods are of interest to cider producers due to the potential for generating unique and complex aromas and flavors via fermentation with naturally present microbiota. The objective of this study was to determine the effect of common pre-fermentation sulfite addition and pH adjustment on cider chemistry and sensory outcomes for naturally fermented high- and low-tannin apple cultivars. Four treatment conditions were applied to both the high- and the low- tannin cultivars: acidification only, sulfites only, acidification and sulfites, and a control with no pre-fermentation juice chemistry adjustment. The eight experimental ciders were fermented using the Pied de Cuve (PDC) method for natural fermentation. Cider chemistry and sensory parameters were determined, and the treatments imparted key differences in both. Key findings were analyzed for pH, titratable acidity, volatile acidity, malic acid, free/total SO2, yeast assimilable nitrogen (YAN), total polyphenols, residual sugars, and ethanol. For the acidified condition, the pH was lowered to 3.2 using malic acid. Cider pH ranged from 3.36 ± 0.04 to 3.72 ± 0.07, reflecting a general trend toward rising pH over the course of fermentation. Juice tannins were 0.244 ± 0.003 g/L for Harrison and 0.12 ± 0.01 g/L for GoldRush. Tannins decreased during fermentation; however, Harrison ciders maintained a higher range compared to GoldRush. Sensory characteristics were determined using a Descriptive Analysis (DA) with a trained panel which produced 28 descriptors. Results were examined via analysis of variance (ANOVA) and significant differences for apple cultivar, acid adjustment, and sulfite use were found for both chemistry and sensory parameters. The interaction between high- and low- tannin content and sulfite use had the most impact on the cider chemistry and sensory attributes. This study helps to shed light on the extent to which pre-fermentation pH adjustment and/or sulfite additions can influence the outcomes of natural cider fermentation in both high- and low-tannin cultivars. / Master of Science in Life Sciences / Cider, also known as "hard cider," is an alcoholic beverage fermented from apples. Virginia is the 6th largest apple producing state in United States and ranks 10th in number of cideries. Natural fermentation uses microorganisms that are present in the environment to ferment cider. This type of fermentation is of interest to the cider industry due to the unique aromas and flavors produced by this method. The objective of this study was to determine the effect of common fermentation management strategies: pre-fermentation sulfite addition and acid adjustment, on cider chemistry and sensory outcomes for naturally fermented high- and low-tannin apple cultivars. Eight experimental ciders were fermented using the Pied de Cuve (PDC) method, which is a type of natural fermentation. Cider chemistry and sensory outcomes were evaluated. The experimental treatments and their interactions imparted key differences in both chemical and sensory outcomes. Cider pH ranged from 3.36 ± 0.04 to 3.72 ± 0.07 reflecting a general trend toward rising pH over the course of fermentation. Juice tannins were 0.244 ± 0.003 g/L for Harrison and 0.12 ± 0.01 g/L for GoldRush. Tannin concentration generally decreased during fermentation; however, Harrison ciders maintained a higher range compared to GoldRush. Sensory characteristics of each cider were determined using a Descriptive Analysis (DA) study, a with a trained panel which produced 28 descriptors, 19 of which were significant. The interaction between high- and low- tannin content and sulfite use had the most impact on the cider chemistry and sensory attributes. This study helps to inform cider producers regarding the impacts of pre-fermentation acid or sulfite additions on natural fermentation, and how those impacts may vary among high- and low-tannin apple cultivars.